Installation guide

AP-IP300 IP Phone Installation Guide Version 1.0
AddPac Technology Proprietary & Documentation
Network & Call – VoIP Setup– PSTN Prefix
When user wants to access the FXO interface for PSTN backup, this prefix number is used as PSTN
access code. Additionally, AP-IP300 IP phone supports the PSTN back-up service when VoIP service
is impossible due to network failure or VoIP call service is interrupted by an exception.
(Figure 4-47) PSTN Prefix Menu
[Table 4-27] Description of PSTN Prefix Menu
PSTN prefix Description
Number Input
PSTN prefix number is an access code for PSTN FXO
interface, default value is #.